Radar is now redundant ?

[Dieseldude]

Originally Posted by BB7

With a large screen displaying GPS location on a super detailed chart, and AIS streaming from every other vessel, I wonder if Radar is now an outdated and redundant technology?
I have radar, but very rarely use it since the GPS chart is better.
Will soon be speccing up a new boat, and wonder if Radar is worth having.

Thoughts from your experience ?

RADAR, GPS chart,and AIS serve different purposes. AIS only aids navigational issues regarding nearby vessels that happen to have AIS and have it functioning. It will not warn you of anything else that can be a hazard, especially during low visibility. Large floating objects, though rare can only be sensed by RADAR at night or in fog. It all comes down to dollars verses benefit. If you can afford it, RADAR is a worthwhile feature to have.

[Happ]

Originally Posted by Mike OReilly

In my travels, there are far more boats out there without AIS than with. Maybe if you're only in rich, urban areas, it might make sense to ditch the radar. Not so in most of the rest of the world.

Besides, AIS doesn't see through fog. It can't track storm cells or fronts. It doesn't show most nav. aids.

And on top of that, I would never rely solely on a chart plotter to know where you are. A chart plotter is a projection of your location that is at least twice removed from reality. It's a great tool, as is AIS, but everyone should understand their limitations.

Mike you nailed it. In my world situational awareness is worth having the radar. I use it in the fog and since most reach out 24 miles I can start to see my destination while having the chart plodder on a more close up view. Tracking weather is huge as well. One more thing. Radar is now really inexpensive as most plodders are set up as a plug and play.

[Tubbs]

Horses for courses and redundancy. GPS isn't always perfect. Notwithstanding hard things not always bleating AIS info, what about a pea-souper and islands, rocks, a difficult harbour entrance, etc? A radar may save you from standing off in uncomfortable conditions for hours on end.

[Richfind]

Originally Posted by Wilyum

How small of an object can radar pick up, say a small submerged log?

At night, water was like glass we were get getting a return right off the bow close in. Couldn't visually see a thing. Creeping up very slowly finally identified the target.

A sea turtle.

Answer: depends, in glassy calm almost anything, in heavy seas, a battleship maybe.

[billk53]

In the Gulf of Mexico radar comes in handy for the oil rigs. They are not all on the charts and they do not all have lights

[BigNut]

Originally Posted by BB7

Fair point re fishing boats, thanks. Rocks are charted adequately, and radar wont find them anyway.

Nooooo!!! They are not, unless you are only a coastal US sailor. I have seen the radar and charts disagree by about half a mile for small islands. Radar can and will find them if they are above the surface.

Not all small fishing boats show up on radar, especially at sea.

Remember also, the COLREGS state that you should be using all available aids at all times, so there is a theoretical legal exposure there, and insurance company weaseling, even in broad daylight.

Radar and AIS are completely different tools, meant for different applications. Use both.

Stay safe out there!

PS I hope this was not a troll.

[makjeng]

Radar remains useful for me as a coastal sailor.
Recently I spotted a potential collision in a very thick fog that persisted for several hours; one vessel had AIS and the other had neither. Having passed close by the latter, I noted their name and about 30 minutes later hailed them on radio to advise their situation which I was monitoring on-screen.
The other vessel with AIS was ID'd so the two of them sorted it out over the air.
A few years ago we sailed through a huge forest fire plume which arrived unexpectedly; there were several small craft caught out as well, but we easily avoided them in the fairly narrow channel via the Radar.
A more frequent usage is finding a place in a crowded anchorage at night. It beats motoring around with a spotlight.
Bottom line: Worthwhile as one of the few information sources not dependent on external inputs.

[edlepera]

Rule 5. Always maintain a proper lookout. Charts paper and electronic ones are not infallible. AIS might not always work. Many smaller vessels don’t always use AIS. Night vision devices that can be used like binoculars are surprisingly getting less expensive. Could be a nice bit of kit to add to the old navigation bag

[JBsurfin]

Originally Posted by BB7

With a large screen displaying GPS location on a super detailed chart, and AIS streaming from every other vessel, I wonder if Radar is now an outdated and redundant technology?
I have radar, but very rarely use it since the GPS chart is better.
Will soon be speccing up a new boat, and wonder if Radar is worth having.

Thoughts from your experience ?

I've yet to see where a chartplotter and AIS can get you through an inlet or follow channel marks in the fog.

[BVIbrian]

AIS is NOT to be used for collision avoidance, period.

The other ship's position is their GPS location, which is frequently incorrect by hundreds of yards: a) the errors inherent to GPS, b) errors due to selective availability sometimes instituted by the DoD, c) the position indicated is the location of the ANTENNA...what if it's on the stern of a 300 meter vessel?

AIS relative vectors do NOT provide the ship's aspect, therefore one cannot properly follow the COLREGS.

AIS true vectors don't tell you where that CPA will occur relative to your vessel.

Things break when least convenient.

AIS is for identification, exactly as the name implies.

Get radar, and get properly trained on how to use it. It might be MY life you save.

[CarlF]

I find it amusing when questions like this bring out the defenders of radar.

Radar is MUCH less important than when I started cruising 30 years ago (with LORAN). Sure, it’s still occasionally helpful but in US waters I normally only use it at night. We cruise Maine most summers and I think I only used it five times last season in fog (less fog these days from climate change).

“Tracking storm cells” is not a good reason to drop $5000 on a radar installation. It’s better done by eye than radar. At night, the lightening is a pretty good hint.

And most people don’t have enough experience with radar to pick out floating objects from the noise.

Every commercial boat over 65ft in the US (and Bahamas/Caribbean) is required to transmit AIS and all the big yachts transmit as it is required by their insurance companies. Smaller fishing boats often don’t transmit but they aren’t as big a collision worry as a 800ft container ship.

So yes, I agree with the OP that chartplotters and AIS have made radar mostly redundant. If you have the money in your budget I’d certainly install radar - especially if you do overnight passages or often cruise in fog. But for most US based cruisers radar is a “nice-to-have” not a “must have”.

[qwerme]

Radar reports every point in space that it sees, AIS only reports the points that are transmitting.

If given a choice between Radar and AIS, Radar is far more useful.

[Statistical]

Originally Posted by BVIbrian

AIS is NOT to be used for collision avoidance, period.

The other ship's position is their GPS location, which is frequently incorrect by hundreds of yards: a) the errors inherent to GPS, b) errors due to selective availability sometimes instituted by the DoD, c) the position indicated is the location of the ANTENNA...what if it's on the stern of a 300 meter vessel?

b) no longer exists and hasn't been used for 20+ years now. The DoD make a public promise to never enable it again even when it was still available (and didn't).

and

c) is completely incorrect unless setup improperly. Any vessel doing that is likely facing liability in any collision if they have mandated AIS usage.



Not saying AIS replaces radar. It doesn't just correct inaccuracies.

Errors inherent in GPS should never be hundreds of meters. That sounds like malfunctioning equipment.

GPS in urban canyons is particularly challenging due to multipath reflections but modern GPS receivers have about 1000x the computing power available for <1W compared to what first generation receivers had so they can even handle those tricky computations with reasonable accuracy. A boat position on the ocean with open sky is about the most trivial of trivial scenarios for a GPS receiver.

[rgranger]

It has already been said but ... yeah! FOG

[JBsurfin]

Originally Posted by CarlF

I find it amusing when questions like this bring out the defenders of radar.

Radar is MUCH less important than when I started cruising 30 years ago (with LORAN). Sure, it’s still occasionally helpful but in US waters I normally only use it at night. We cruise Maine most summers and I think I only used it five times last season in fog (less fog these days from climate change).

“Tracking storm cells” is not a good reason to drop $5000 on a radar installation. It’s better done by eye than radar. At night, the lightening is a pretty good hint.

And most people don’t have enough experience with radar to pick out floating objects from the noise.

Every commercial boat over 65ft in the US (and Bahamas/Caribbean) is required to transmit AIS and all the big yachts transmit as it is required by their insurance companies. Smaller fishing boats often don’t transmit but they aren’t as big a collision worry as a 800ft container ship.

So yes, I agree with the OP that chartplotters and AIS have made radar mostly redundant. If you have the money in your budget I’d certainly install radar - especially if you do overnight passages or often cruise in fog. But for most US based cruisers radar is a “nice-to-have” not a “must have”.

I see radar like insurance.. You don't need it, until you need it..